KR20170074803A - Wire electric discharge machine - Google Patents

Abstract

A core wire image obtaining means is mounted at a position overlooking the workpiece on the table such as a wire guide machine upper guide and the like, and the core wire is fixed while fixing the core wire using the wire fixing function, and the end point of the machining path The image of the core and the workpiece is picked up by the central image pick-up means, and it is judged whether or not there is a certain width of the machined groove from the picked-up image, whether there is adherence or deposit of the processing debris in the machined groove, It is determined whether or not the core is fixed by the difference in the state. If the core is not fixed, the machining is stopped, and the machining is confirmed by confirming the fixing of the core, so that the continuous machining can be safely performed. In addition, in the case where the core is not fixed and dropped, the machining is stopped, so that breakage of the nozzle, the wire guide, and the like can be prevented.

Description

[0001] WIRE ELECTRIC DISCHARGE MACHINE [0002]

The present invention relates to a wire electric discharge machine, and more particularly to a wire electric discharge machine in which a machining debris is adhered to and deposited on a workpiece and a core in a part of a machining groove formed by electrical discharge machining, To a wire electric discharge machine having a core fixing function.

In a wire electric discharge machine, a function of attaching and depositing (depositing) processing debris to a machining groove of a workpiece by using a phenomenon of adhesion of a wire component to the workpiece and fixing the machined core to the workpiece Fixed function ") is known. In this core fixing function, a method has been employed in which machining is carried out while fixing each of a plurality of generated cores, and an external force is applied to each of the fixed cores after completion of all machining, thereby removing the core from the workpiece . Since this method is efficient, it is effective in the processing in which a large number of characters are generated.

For example, in Japanese Unexamined Patent Application Publication No. 2012-166332, when a machining shape is machined, at least one point of the machined shape is replaced with a welding cycle in the machining cycle, and a part of the wire electrode is melted , The workpiece and the cut material are melted by the wire electrode melt to prevent the cut material from falling off, and the welded portion is broken by the external force after the completion of the electric discharge machining to remove the cut material from the work. Japanese Laid-Open Patent Publication No. 2014-24132 discloses a method of analyzing a machining program to calculate a machining circumference length of a machining member cut out from a workpiece and a top surface area of the shape of the machining member, A wire discharge for calculating the length of the welded portion of the machining member with respect to the calculated mass from a map storing the relationship between the mass of the machining member and the length of the welded portion capable of holding the machined member, A method of editing a part program for a processing machine is described.

In addition, Japanese Laid-Open Patent Publication No. 2014-14907 discloses a wire electric discharge machine and a wire electric discharge machine capable of arbitrarily setting their fixing points when fixing the core body to the work base material by attaching and depositing the processing debris to the work groove. Device is described.

In addition, Japanese Laid-Open Patent Publication No. 2013-144335 also discloses a wire electric discharge machine in which an attachment region for attaching a component of a wire electrode is set from the shape and weight of a middle string to prevent falling of the middle string, A machining program generating apparatus of the present invention is described.

When the method of fixing the core by the above-mentioned core fixing function is employed, it is not necessarily fixed. There has been a problem in that the core is not fixed to the workpiece due to various causes such as a mistake in various settings, a change in the quality of the processing liquid, an aging change in the wire electric discharge machine itself, and the like. For example, when the core 6 is not fixed and the core 6 is caught by the nozzle 5a as shown in Fig. 5 (B), if the nozzle 5a is moved in the right direction in this state, The core 6 is sandwiched between the nozzle 5a and the workpiece 3, causing a problem of damaging the nozzle 5a and the wire guide portion. Of course, continuous machining is not possible, and repair of the machine is also required, resulting in a long machine down time. In addition, there is also a problem that when the wire electrode breaks during machining, the fixed portion is destroyed when returning to the uncoiling position after automatic connection. As a result of such a problem, there has been a user of the wire electric discharge machine that the core fixing function is scary and can not be used.

It is therefore an object of the present invention to confirm that the core is fixed by machining using the core fastening function, and to stop the machining when it is not fixed.

A wire electric discharge machine according to the present invention is a wire electric discharge machine in which a wire electrode and a workpiece are moved relative to each other in accordance with a machining program to discharge the workpiece by a discharge generated between the wire electrode and the workpiece, A central character image acquiring means for acquiring an image of the central character and having a center fixing function for fixing the central character generated by the electrical discharge machining and the processing member by attaching and depositing the generated debris to the machining groove; An image capturing means for capturing an image obtained by the image capturing means; and an image capturing means for capturing the image captured by the image capturing means, When the fixing state of the middle string is confirmed And one that allows you to perform the machining features.

The wire electric discharge machining apparatus is characterized in that the medium fixed state determining means determines whether or not the wire is fixed by determining whether the width of the machining groove surrounding the core formed by the electric discharge machining from the image is constant or falls within a predetermined allowable range, Or not. It is preferable that the wire electric discharge machine further comprises a determination means for judging whether the core is fixed or not based on whether the adhesion or deposit of the processing debris generated by the electric discharge machining is present in the machining groove from the image, . It is preferable that the wire electric discharge machine is configured to determine whether the heavy wire is fixed by the difference between the state of the wire and the surface light of the workpiece from the image.

The wire electric discharge machining apparatus is characterized in that in the step of finishing machining up to the end point of the machining path for cutting out the core, or in the stage where the fixing process by the core fixing function is finished, It is determined whether or not the image is fixed.

The wire electric discharge machining apparatus is configured to move the middle image obtaining means by mounting the middle image obtaining means on the robot.

According to the present invention, since the machining proceeds by confirming the fixing of the core, the continuous machining can be safely performed. Further, according to the present invention, when the core is not fixed but dropped, the machining is stopped, so that breakage of the nozzle, the wire guide, and the like can be prevented.

The above and other objects and features of the present invention will become apparent from the following description of the embodiments with reference to the accompanying drawings. Among these drawings:
1 is a schematic diagram of an embodiment of the present invention.
2 is a schematic diagram of another embodiment of the present invention.
3A is an explanatory diagram for judging a fixed state of an image from an image in which the width of the processed groove is kept constant.
Fig. 3B is an explanatory diagram for judging the fixed state of an image from an image in which the width of the processed groove is not constant. Fig.
Fig. 3C is an explanatory diagram for judging the solid state from other images in which the width of the processed groove is not constant. Fig.
Fig. 4A is an explanatory diagram for judging a fixed state of an image from an image having a fixed portion in a machined groove; Fig.
Fig. 4B is an explanatory diagram for judging the fixed state of an image from an image having no fixed portion in the machined groove; Fig.
Fig. 4C is an explanatory diagram for judging the fixed state of the core from another image having no fixed portion in the machined groove; Fig.
FIG. 5A is a view for explaining a fixed state of a middle string; FIG.
Fig. 5B is a view for explaining the unfixed state of the core. Fig.
Fig. 6A is a diagram showing that the core is fixed and the reflection condition of light on the surface of the core and the workpiece are the same, in the explanatory diagram for determining the fixed state of the core from the surface light state of the core and the work.
Fig. 6B is a diagram for explaining that the core and the workpiece are not fixed, and the reflection state of light on the surface of the core and the workpiece are different. Fig.
Fig. 6C is a view for explaining that the core and the workpiece are not fixed, and the reflection state of light on the surface of the core and the workpiece are different.
FIG. 7A is a diagram showing an example of a middle character. FIG.
Fig. 7B is a view for explaining an example of plural machining of the core shown in Fig. 7A.
Fig. 8 is a flowchart showing an algorithm of the fixed state determining process performed by the processor of the control apparatus of the wire electric discharge machine.

BRIEF DESCRIPTION OF THE DRAWINGS Fig.

The present invention is characterized in that a confirmation means for confirming that the key is fixed to the workpiece is formed, and this confirmation means is characterized by forming a key image acquisition means such as a visual sensor or an image pickup apparatus.

1 is a schematic diagram of an embodiment of the present invention. The center image acquisition means 1 constituted by the visual sensor or the imaging device is mounted at a position overlooking the table 2 on which the workpiece 3 such as the upper guide portion 4 of the wire electric discharge machine is mounted . Is mounted above the upper guide portion 4 in the embodiment shown in Fig. The central image acquisition unit 1 is connected to a control unit (not shown) for controlling the wire electric discharge machine, and acquires an image of the work 3 by a command from the control unit and transmits the image to the control unit . Reference numeral 4a denotes an upper nozzle, 5a denotes a lower nozzle, and 5 denotes a lower guide.

Fig. 2 is an outline of another embodiment of the present invention, in which the body image acquisition means 1 is attached to the robot 10. Fig. The control device of the robot 10 is connected to a control device of a wire electric discharge machine (not shown). In the case of this embodiment, when acquiring the middle image, the upper guide 4 is retracted, the robot 10 is driven, and the middle image acquisition means 1 is set at the middle image acquisition position instructed by the processing program And acquires an image, or locates and reproduces the middle position by the middle image obtaining means based on the image data of the middle character registered in advance.

The present invention judges the fixed state of the middle character based on the image acquired by the medium image acquisition means (1). As a judgment method, there is a judgment method such as whether the width of the processed groove is constant, whether there is the adhesion / deposition (sticking portion) of the processing debris in the processing groove, or whether there is a difference in the reflective state of light between the middle and the surface of the processing object.

1) Method for determining the fixed state of the core by whether the machining groove width is constant.

Fig. 3 is an explanatory diagram for judging from the image acquired by the medium-and-medium image acquiring means 1 the medium-fixed state from the width of the machined groove.

The working groove width produced by the wire discharging process is almost constant according to the wire diameter, and falls within a predetermined allowable range. Therefore, in the image acquired by the medium image acquisition means 1, if the middle character 6 is fixed by the intermediate fixing function even after completion of cutting of the middle character, as shown in Fig. 3A, the width of the processing groove 7 becomes The image is kept constant. 3B and 3C, the image obtained by the middle-size image obtaining means 1 is cut off from the processing groove 7 (Fig. 3B). On the other hand, ) Is not fixed. Therefore, it is possible to judge the fixed state of the medium by whether or not the machining groove width is within the allowable range determined from the image acquired by the medium image obtaining means 1. [

2) Determination of the fixed state of the core by the presence of a fixing part in the machining groove.

The core fixing function fixes the core by attaching and depositing the processing debris in the machining groove. Therefore, in the image obtained by the central image acquisition means 1, when the core 6 is fixedly connected to the workpiece 3, as shown in Fig. 4A, in the machined groove 7, (Adhered portion) 11 of the film is present. On the other hand, in the case where the core 6 is not fixed, the core 6 is cut off, and therefore, as shown in Figs. 4B and 4C, there is no adhesion or deposition of the processed debris (fixed portion) Is not obtained. Therefore, it is possible to judge the fixed state by the presence or absence of the sticking portion in the machining groove from the image acquired by the medium image acquisition means 1. [

3) A method for determining the fixed state of the core by difference in reflection state of light between the core and the surface of the member to be processed.

When the core 6 is fixed to the workpiece 3, the core 6 and the surface of the workpiece 3 are on the same plane as shown in Fig. 5A, and the reflection state of the light from both surfaces . On the other hand, in the case where the core 6 is not fixed, as shown in Fig. 5B, since the core 6 and the surface of the work 3 are not on the same plane, Are different. Fig. 6 is an example showing the reflection of light on the surface of the workpiece and the center of the image acquired by the medium-and-medium image acquiring means 1. Fig.

6A shows that the core 6 is fixed and the reflection condition of light on the surface of the core 6 and the surface of the work 3 is the same. 6B and 6C show that the core 6 is not fixed and the reflection state of light on the surface of the core 6 and the surface of the work 3 is different. Therefore, the fixed state of the core 6 can be determined by analyzing the intensity and the spectrum of the surface light of the core 6 and the work 3. [

Next, as shown in Fig. 7A, the rectangular solid 6 having the length in the X-axis direction 10 and the length in the Y-axis direction 8 is cut from the work 3 to 1 ), (2), (3), and (4) in this order. The processing start hole h is machined at an intermediate position (X = 5, Y = 4) of the length of the core 6 in the X-axis and Y-axis directions, .

The machining program is as follows.

<Main program>

O2000;

S1D1; ... 1st machining condition, offset setting

M98P200; ... Call subprogram 1

G00X-45.0;

M00; ... Program stop

S2D2; ... 2nd machining condition, offset setting

M98P230; ... Call subprogram 3

G00X-45.0;

S3D3; ... 3rd Machining Condition, Offset Setting

M98P230; ... Call subprogram 3

M30;

<Subprogram 1>

O200;

M60; ... Wire connection

M98P220; ... Subprogram 2 call (processing of the middle part of (1))

M50; ... Wire cutting

M123; ... Determination of fixed state of middle

G00X15.0;

M60; ... Wire connection

M98P220; ... Subprogram 2 call (machining of the middle part of (2))

M50; ... Wire cutting

M123; ... Determination of fixed state of middle

G00X15.0;

M60; ... Wire connection

M98P220; ... Subprogram 2 call (processing of the middle part of (3))

M50; ... Wire cutting

M123; ... Determination of fixed state of middle

G00X15.0;

M60; ... Wire connection

M98P220; ... Subprogram 2 call (machining of the middle part of (4))

M50; ... Wire cutting

M123; ... Determination of fixed state of middle

M99;

<Subprogram 2>

O220;

G92X0.0 Y0.0; ... Coordinate system setting

G91G01G42Y-4.0; ... Cutting feed (discharge machining section)

X-5.0; ... Cutting feed (discharge machining section)

Y8.0; ... Cutting feed (discharge machining section)

X10.0; ... Cutting feed (discharge machining section)

Y-8.0; ... Cutting feed (discharge machining section)

X-5.0; ... Cutting feed (discharge machining section)

G40Y4.0; ... Cutting feed (discharge machining section)

M99;

<Subprogram 3>

O230;

M60; ... Wire connection

M98P220; ... Subprogram 2 call (processing of the middle part of (1))

M50; ... Wire cutting

G00X15.0;

M60; ... Wire connection

M98P220; ... Subprogram 2 call (machining of the middle part of (2))

M50; ... Wire cutting

G00X15.0;

M60; ... Wire connection

M98P220; ... Subprogram 2 call (processing of the middle part of (3))

M50; ... Wire cutting

G00X15.0;

M60; ... Wire connection

M98P220; ... Subprogram 2 call (machining of the middle part of (4))

M50; ... Wire cutting

M99;

In the main program O2000, the sub-program 1 (O200) is read out from "M98P200" after the processing condition of the 1st cut is set in "S1D1". In the sub program 1 (O200), wire connection is instructed in "M60", and sub program 2 (O220) in "M98P220" is called. In the sub program 2 (O220), a coordinate system having the origin of the machining start hole h of the center 6 of the current position 1 in "G92X0.0 Y0.0" is set, and "G91G01G42Y-4.0 4 direction in the minus direction of the Y axis by the command of the cutting feed (G01) and the wire offset right (G42) by the incremental G91 and then the 5th and the Y axis in the minus direction of the X axis The wire offset is canceled (G40) by 8 in the plus direction, 10 in the X axis positive direction, 8 in the Y axis minus direction, 5 in the minus direction of the X axis and moved in the Y axis positive direction by 4, 4, X - 5, Y + 8, X + 10, Y - 8, X - 5 and Y + 4 from the machining start hole And returns to the position of the machining start hole h.

Then, the subroutine 2 (O220) returns to the subprogram 1 (O200) by the instruction of "M99", the wire is cut at "M50" of the subprogram 1 (O200), and by the command of "M123" (This processing will be described later) is performed. When it is determined that the inside character is fixed, the position is determined by moving 15 in the X-axis direction by the instruction of &quot; G00X15.0 &quot;.

(2) and (3), which are positioned at the position of the machining start hole h of the core 6 of (2) and are machined in the same manner as the machining of the core 6 of (1) ), And processing of the core 6 of (4). Then, the main program O2000 returns from the "M99" to the main program O2000. In the main program O2000, by the positioning command of "G00X-45.0" The X axis is moved in the minus direction 45 to move to the position of the machining start hole h of the center pin 6 of the pin 1 and the four pinions 6 are machined as shown in Fig. Further, at the point of time when the program operation is stopped after "M00" is commanded after the completion of the first cut, the middle piece 6 is removed by the worker applying an external force by the hammer, and the finish processing of the 2nd cut and the 3rd cut Is performed along sub-program 3 (O230).

When the "M123" fixed-state determination command is output in the above described machining program, the processor of the control device (not shown) of the wire electric discharge machine starts the processing shown in Fig.

The process shown in Fig. 8 shows the process when the middle-size image obtaining means 1 is mounted on the robot as shown in Fig. Therefore, first, in step S1, the upper guide portion is retracted (since the wire has been cut by the instruction of "M50", it can be moved) by the M123 command. Next, the control command of the robot 10 (Step S2). The control device of the robot 10 moves the central image acquisition means with the aim of the coordinate position (position of the processing start hole h) instructed by the coordinate system setting of G92 in the machining program. Alternatively, on the basis of the image data of the middle name registered in advance, the middle character image acquiring means finds the position of the middle character and photographs it. Then, the picked-up image is sent to the control device of the wire electric discharge machine.

The control device of the wire electric discharge machine obtains the image data of the sent-in core (step S3), and judges whether or not the above-mentioned three methods (judging whether the machining groove width is constant, (Determination based on the reflection state of light on the surface of the workpiece and the inner surface of the workpiece) (step S4).

(Step S9). When the robot 10 has determined that the middle character is fixed, the robot 10 outputs a withdrawal instruction of the middle character image obtaining means 1 to the control device of the robot 10 And the upper guide is returned to the pre-evacuation position (step S10). The processing of the M123 command is terminated, and the program returns to the original sub-program 1 and the program operation after the M123 command is resumed.

On the other hand, if it is determined in step S4 that the key is not fixed, the control unit of the robot 10 outputs a save command of the key image acquisition unit 1 (step S5), and the key image acquisition unit 1 (Step S6), the program operation is stopped (step S7), the alarm display is made (step S8), and the discharge machining is stopped and the process is terminated.

In the embodiment described above, an example of instructing the determination of the fixed-body state by using the cordless-fixing-state determining code such as &quot; M123 &quot; is shown. However, , The same processing as that of Fig. 8 described above may be performed after the wire cutting of the M50 command.

The process shown in Fig. 8 is a process performed when the middle-size image obtaining means 1 shown in Fig. 2 is attached to the robot. However, as shown in Fig. 1, When the workpiece 3 such as the workpiece 4 is mounted at a position overlooking the table 2 on which the workpiece 3 is placed, processing for returning the upper guide portion of the steps S1, S6, and S10 to the pre- And there is no need to perform the evacuation processing (evacuation instruction for the robot) of the medium image acquisition means in steps S5 and S9. The imaging instruction in step S2 is not to be outputted to the robot 10 but to be outputted to the medium image acquisition means 1. [ As shown in Fig. 1, when the center image acquisition means 1 is mounted at a position overlooking the table 2 on which the workpiece 3 is placed, an image of the base body 6 can always be obtained . When the fixing process by the intermediate fixing function is finished, the image pickup instruction is outputted to the medium image obtaining means (1), and it is judged whether or not the intermediate image is fixed from the obtained image. And if it is determined that it is not fixed, the operation may be stopped to display an alarm.

As described above, in the present embodiment, it is possible to confirm whether the core wire is fixed in the wire electric discharge machining while fixing the core wire by using the core wire fixing function, so that it is possible to perform the machining safely.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, but can be implemented in other modes by adding appropriate modifications.

Claims (6)

The wire electrode and the workpiece are relatively moved in accordance with the machining program and the workpiece is subjected to electric discharge machining by discharging generated between the wire electrode and the workpiece and the machining debris generated by the electric discharge machining is attached A wire electric discharge machine having a wire fastening machine for fastening a wire to a work and fixing the wire to be machined by the electric discharge machining by depositing the wire,
A medium-fixed-state determining means for determining whether or not the medium character is fixed based on the image obtained by the medium image obtaining means,
And an electric discharge machining stopping means for stopping said electric discharge machining when said medium and fixed state determining means determines that said medium is not fixed. The method according to claim 1,
The medium fixed state determining means determines whether or not the center is fixed based on whether the width of the machining groove surrounding the center formed by the electrical discharge machining from the image is constant or falls within a predetermined allowable range , Wire electric discharge machine. The method according to claim 1,
Wherein the central fixed state determining means determines whether or not the core is fixed based on whether or not the adhering / depositing of processing debris generated by the electric discharge machining is present in the machining groove from the image. The method according to claim 1,
Wherein the medium fixed state determining means determines whether or not the middle string is fixed based on a difference between a state of the surface light of the medium and the surface of the member to be processed from the image. 5. The method according to any one of claims 1 to 4,
Wherein the central fixed state determining means determines whether or not the central character is obtained from the image obtained by the central character image obtaining means at the stage where the machining is finished up to the end point of the machining path for cutting out the central character, And determines whether or not the wire is fixed. 6. The method according to any one of claims 1 to 5,
And the central image acquisition means is mounted on the robot so that the central image acquisition means can be moved.

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